What is the expected lifetime of the ESA Series L1500A spectrum analyzer IF relays?

The analyzer's IF relays are specified for one BILLION cycles. Therefore, if the relays switched three times per second, and the analyzer was left on for 24 hours a day, the relays should last 10 years. This life is extended even further by slowing down the switching rate. As the analyzer's temperature stabilizes, the IF hardware drift is reduced to the point where it is not necessary to perform realignments as frequently as when the analyzer power was just switched on, conserving relay life.